Carbon belt drive is “future for bike transmission”

Belt drives are nothing new in the bike industry. Many have been tried in the distant past and, more recently, there have been rubber/Kevlar belt drives but none have had the efficiency of ye olde bicycle technology: the roller chain.

However, in 2004 Brit Errol Drew introduced the belt-drive iXi bike via his US company, Delta. He said his composite belt drive had 98 percent efficiency, "the same as a chain."

Belt drives keep cropping up because they don’t require lubrication so won’t smear the rider with oil. They promise almost zero-maintenance riding. A good, efficient belt drive system would be perfect for utility bikes. Smooth, silent, and clean, an efficient, super-strong belt drive system could be considered the Holy Grail of bicycle transmission.

And it’s now within grasp, thanks to Gates of Dumfries. The company produces belt drive transmission systems for car makers Audi and BMW, and factory belt drives for Heinz and other major manufacturers. Looking to diversify into the bike trade, company officials were at the Taipei trade show earlier this year. Michael Bonney of Orange – not, it must be said, a noted maker of utility bikes – hooked up with the Gates crew and spotted the massive potential of the company’s carbon belt drive.

Orange produced a single speed prototype bike for testing in this summer’s 24-hour MTB races. It made it through claggy conditions without maintainance.

A belt driven bike "rides differently," Bonney told BikeBiz.

"It’s a totally different feel. I got tired of explaining this at Eurobike. I just let people ride the bike. Everybody was very impressed."

Chipps of Singletrack magazine said: "You expect to feel the ‘give’ in the belt, but there is none at all. None! The ride feel is more akin to a track bike with a super tight chain."

The bike on display at Eurobike used Shimano’s Alfine 9-speed internal hub. Industry execs from most of the big players – including component suppliers – pored over the Orange bike.

The belt drive is one-piece composite protected with a rubberised outer. Gates calls it the Poly Chain GT Carbon belt and says it "outperforms a roller chain in even the most demanding high-torque applications."

Spot Bikes of the US is also running with a Gates belt drive. There’s a promo video here.